An atomistic investigation on the wear of diamond during atomic force microscope tip-based nanomachining of gallium arsenide
An atomistic investigation on the wear of diamond during atomic force microscope tip-based nanomachining of gallium arsenide
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DOI：
10.1016/j.commatsci.2020.110115
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发表时间：
2021-02-01
影响因子：
3.3
通讯作者：
Wang, Yuzhang
中科院分区：
文献类型：
--
作者：
Fan, Pengfei;Goel, Saurav;Wang, Yuzhang
采用分子动力学模拟方法研究了原子力显微镜（AFM）针尖加工砷化镓（GaAs）过程中金刚石的磨损机理。在模拟过程中观察到的金刚石尖端的顶点处的弹塑性变形。同时，金刚石针尖从其初始的立方金刚石晶格结构sp（3）杂化到石墨晶格结构sp（2）杂化的转变被揭示。石墨化，因此，被认为是占主导地位的磨损机制的金刚石针尖在纳米切割单晶砷化镓的第一次。各种应力状态，如静水应力，剪切应力，和冯米塞斯应力内的金刚石尖端和温度分布的金刚石尖端也估计，找出石墨化的潜在机制。结果表明，GaAs纳米加工过程中的切削热主要导致金刚石针尖的石墨化，而不是高剪切应力诱导的金刚石向石墨的转变。本文还提出了一种新的方法来量化的石墨化转化率的金刚石针尖。
This paper investigated the wear mechanism of diamond during the atomic force microscope (AFM) tip-based nanomachining of Gallium Arsenide (GaAs) using molecular dynamics (MD) simulations. The elastic-plastic deformation at the apex of the diamond tip was observed during the simulations. Meanwhile, a transition of the diamond tip from its initial cubic diamond lattice structure sp(3) hybridization to graphite lattice structure sp(2) hybridization was revealed. Graphitization was, therefore, found to be the dominant wear mechanism of the diamond tip during the nanometric cutting of single crystal gallium arsenide for the first time. The various stress states, such as hydrostatic stress, shear stress, and von Mises stress within the diamond tip and the temperature distribution of the diamond tip were also estimated to find out the underlying mechanism of graphitization. The results showed that the cutting heat during nanomachining of GaAs would mainly lead to the graphitization of the diamond tip instead of the high shear stress-induced transformation of the diamond to graphite. The paper also proposed a new approach to quantify the graphitization conversion rate of the diamond tip.